OFDM

Using OFDM signals in wireless communication

OFDM, orthogonal frequency-division multiplexing, is a widely used digital modulation method in wireless communications, such as WLAN, LTE, DVB-T, and 5G. OFDM belongs to the class of multicarrier modulation schemes. OFDM decomposes the transmission frequency band into a group of narrower contiguous subbands (carriers), and each carrier is individually modulated. Such a modulation can be easily implemented by an inverse fast Fourier transform (IFFT). By using narrow orthogonal subcarriers, the OFDM signal gains robustness over a frequency-selective fading channel, and eliminates adjacent subcarrier crosstalk. At the receiving end, the OFDM signal can be demodulated with a fast Fourier transform (FFT) and easily equalized with a complex gain at each subcarrier. Several new forms of OFDM have been proposed for 5G applications, such as CP-OFDM, F-OFDM, W-OFDM, GFDM, UFMC, and FBMC.

Single carrier modulation and OFDM in time and frequency domains.

Communications System Toolbox™, WLAN System Toolbox™, and LTE System Toolbox™ and its 5G Library offer various OFDM functionalities. These toolboxes provide general or standard-compliant functions for the simulation, analysis, and testing of the OFDM waveforms. The toolboxes also provide end-to-end transmitter/receiver system models with configurable parameters and various wireless channel models to help evaluate the wireless systems that use OFDM waveforms. Specifically, as a part of wireless communication system design, you can use these OFDM capabilities to analyze link performance, robustness, system architecture options, channel effects, channel estimation, channel equalization, signal synchronization, and subcarrier modulation selections.